Giant goby

Gobius cobitis

This large goby is a very rare find in Britain
because the giant gobies found here are on the northern edge of
their natural distribution. They cannot breed in the colder waters
further north, as they are really a southern European fish. Perhaps
changes in seawater temperature as a result of climate change will
see the gobies moving further north.

Gobies are small, familiar rock pool fish, but this one really
is a giant – up to 27 cm long. Giant gobies live in rock pools high
up on sheltered shores and seem to prefer brackish seawater, which
is not fully salty. They can withstand the large temperature
changes experienced in the rock pool environment, and may even be
seen ‘basking’ in the sun on exposed rocks within the pool.

They have a broad diet, including green seaweed, worms,
shrimp-like animals, small fishes, and insects. They are quite
long-lived, with a lifespan of ten years. Females can lay up to
12,000 eggs at a time, which are guarded by the attentive male.

Although there is no evidence that giant gobies are endangered
in the UK, it seems likely that they are vulnerable to human
disturbance from visitors to the seashore.

European distribution

In the UK, the giant goby is known only from the coasts of
south-west England between Wembury and the Isles of Scilly, and in
the Channel Islands. Outside of the UK, it is found from the
western English Channel to Morocco, in the Mediterranean and the
Black Sea.